A preliminary survey of the estuaries on the southeast coast of South Africa, Old Woman's – Tyolomnqa, with particular reference to the fish fauna

Abstract

A basic ichthyofaunal and physico-chemical survey of estuaries on the southeast coast of South Africa from Old Woman's to Tyolomnqa (former Ciskei Region of the Eastern Cape) was undertaken during September 1996. Sixteen coastal outlets have been identified along this stretch of coastline. The greatest diversity of fishes was found in the permanently open Keiskamma and Tyolomnqa estuaries and this can be attributed in part to the permanent connection with the sea that allows year-round access for marine species. Ten systems were predominately closed estuaries and, although supporting lower species diversity also provided important habitat for a number of estuarine-dependent marine species as well as resident species, which were often recorded in high numbers. One system was a small coastal stream, which is of limited value for estuarine-associated fishes. Three of the systems were dry stream beds and provided no habitat for fishes. Twelve of the estuaries in this region therefore provide important habitat for estuarine-associated species and also support a number of endemic species which further emphasises the importance of these estuaries in maintaining ichthyofaunal diversity in the region.